Speed governor



Dec. 21, 1948.

l. J. sNADER ETAL 2,456,747

SPEED GOVERNOR Filed March 23, 1944 2 Sheets-Sheet l Dec. 21, 1948. l. J. sNADER ErAL SPEED GOVERNOR 2 Sheets-Sheet 2 Filed March 255, 1944 Patented Dec. 2l, 1948 SPEED GOVERNOR Ira J. Snader, Detroit, Mich., and Archibald Graham Forsyth, Cheam, England. assigner: of one-half to Avco Manufacturing Corporation, a corporation of Delaware, aand one-half to The Fairey Aviation Compa sex, England ny,` Ltd.,-Hayes, Middle- Application March 23, 1944, Serial No. 521,836

The l'present invention relates generally to governor mechanisms for speed controlling purposes. More particularly the invention relates to that type of governor mechanism which is primarily designed for use in connectionv with an airplane having a controllable pitch propeller and a propeller driving internal combustion engine, and operates by varying the pitch or attack angle of the propeller blades to control or govern the engine so that it operates at a predetermined speed.

One object of the invention is to provide a governor mechanism of this type which is an lmprovement upon, and has certain advantages over, previously designed governor mechanisms for the same purpose and is characterized by the fact that it embodies a novel arrangement of parts and involves a new mode of operation.

Another object of the invention is to provide a governor mechanism of the type under consideration which, due to its design and construction, so controls the engine that the latter in connection with either gradual or abrupt acceleration or deceleration is quickly brought back to its predetermined speed with a minimum of so called hunting action.

A further object of-the invention is to provide a governor mechanism of the last' mentioned character which is adapted to be driven by the engine to be governed and comprises in addition to an engine driven member and coacting elements for effecting control of the speed of the engine, means operative in response to variation in the speed of the member due to gradual variation of the speed of the engine from its predetermined speed to actuate the elements so that they result in the engine returning to its predetermined speed, and means operative in response to variation in the speed of the member due to anv abrupt variation in the speed of the engine substantially instantaneously to actuate the elements so they result in the engine returning to its predetermined speed, and in which the means responsive to abrupt variation in the speed of the engine is independent of, or separate from, the means that is responsive to gradual variation in the speed of the engine.

A still further object of the invention is to provide a governor mechanism which effectively and eiliciently fulfills its intended purpose and not only is simple in design but also may be produced at a comparatively low cost.

Other objects of the invention and the various advantages and characteristics of the present governor mechanism will be apparent from s cimas. (ci zes-11) 2 a consideration of the following detailed description.

The invention consists in the several novel features which are hereinafter set forth and are more particularly denned by claims at the conclusion hereof.

In the drawings which accompany and form a part of this specincation or disclosure and in which like numerals of reference denote corresponding parts throughout the several views:

Figure l is a front elevation of a governor mechanism embodying the invention, certain parts of the housing of the mechanism being broken away or omitted forv illustrative purposes;

Figure 2 is a vertical longitudinal section of the governor mechanism taken on the line 2-2 of Figure l and illustrating in detail the design and arrangement of the various operating parts of the mechanism;

Figures 3, 4, 5 and 6 are vertical transverse sections taken respectively on the lines 3 3. 4 4, 5 5 and 6-6 of Figure 2;

Figures 7 and 8 are fragmentary perspective views of certain parts of the means for substantially instantaneously actuating the engine controlling elements when the speed of the engine driven member varies due to abrupt acceleration or deceleration of the engine with which the mechanism is associated.

The governor mechanism which is shown in the drawings constitutes the preferred form or embodiment of the invention. It is primarily designed or adapted for use in connection with an airplane (not shown) having a controllable pitch propeller and a propeller driving internal combustion engine (both not shown) and, as hereinafter described, operates by varying the angle of the propeller blades to govern or control the engine so that it runs at a predetermined speed. As its primary or principal parts the mechanism comprises a housing l0, an engine driven member in the form of a shaft Il, an electric pilot motor l2 and a diilerential type gear unit Il.

'I'he housing i0 surrounds and supports the various operating parts of the governor mechanism and is formed of a plurality of complemental detachably connected sections in order that it may be dismantled in connection with assembly or removal of such operating parts. It is horizontally elongated as shown in Figure 2 and comprises a front wall I4, a rear wall I6 and a pair of upstanding partitions It and I1 in addition to top, bottom and side walls. The front and rear walls of the housing extend vertically and are spaced apart by the top, bottom and 3 side walls. The front wall is provided at its upper portion with a horizontally extending open ended tubular part l2 and this extends longitudinally of the housing and is provided at its front end with an integral outwardly extending annular flange I9. The latter is provided with apertures for receiving bolts or other attaching devices whereby the governor mechanism as a whole may be xedly retained in its desired operative position with respect to the internal combustion engine that it is designed to control.

The rear wall 'I5 of the housing is disposed in parallel relation with the front wall I4 and supports an exteriorly disposed cup-shaped subhousing- 2|. The latter extends horizontally and has the free margin of the continuous side wail thereof bolted or otherwise fixedly secured to the central portion of the rear wall I5. The interior of the sub-housing 2| communicates with the interior of the mainvhousing III by way of an opening 22 in said central portion of the rear wall I5. 'Ihe upstanding partition I6 is located adjacent, but spaced inwards of, the front wall i4. It extends transversely of the housing and is arranged in parallel relation with said front wall I4. The upstanding partition I1 is located adjacent, but spaced inwards of, the rear wall I5 and, like the partition I6, extends transversely of the housing. The two partitions i6 and I1 are spaced apart as shown in Figure 2.

'I'he shaft II constituting the engine driven member of the governor mechanism extends horizontally. It extends longitudinally through, and is in centered relation with, the tubular part I8 at the upper end of the front wall I4 of the t housing and is supported for rotation about the longitudinal axis thereof by way of an outer ball bearing 23 and an inner ball bearing 24. 'I'he outer races of such bearings are suitably secured to the end portions of the tubular part I8. The outer end of the shaft is adapted to be connected by a flexible shaft or other coupling (not shown) to one of the driven elements or parts of the engine, such, for example, as the cam shaft, in order that the shaft II is driven conjointly with the engine. The inner end of the engine driven shaft II extends through an opening 25 in the upper end of the partition I6 and terminates in the space between the tWo partitions. For purposes of the present disclosure it will be assumed that the engine driven shaft II is driven by the engine in a counterclockwise direction as viewed in Figure 5 (see arrow in Figure 2).

The electric pilot motor I2 is located at the rear of the housing I0 and comprises a casing 28 and an armature shaft 21. It is so positioned that the armature shaft 21 thereof is in axial alignment with the engine driven shaft Il. 'I'he casing of the electric pilot motor I2 is disposed exteriorly of the housing and is provided at the inner end thereof .with an outwardly extending annular flange which is bolted or otherwise fixedly secured to the upper portion of the rear wall l5 of the housing. The inner end of the armature shaft 21 of the motor extends through openings or holes in the rear wall I5 and the partition I1 of the housing and terminates in the space between the two partitions I I and I1. A battery 28 serves to supply electric current to the pilot motor I2. One side of the battery is connected to one of the terminals of the motor by way of a conductor 22. The other side of the battery is connected to the motor terminal by way of a conductor 22. The last mentioned conductor is provided with a switch 2I and a rheostat 32. The rheostat serves as a medium for varying the speed of the electric pilot motor I2 when the switch 2| is closed. The motor is so designed that the armature shaft 21 thereof rotates reversely to the engine driven shaft II, i. e., in a clockwise direction as viewed in Figure 4 (see arrow in Figure 2). When the electric pilot motor I2 is in operation the governor, as hereinafter described, operates to control the engine so that it runs at a predetermined speed, i. e., a speed which is directly proportional to the speed of the pilot motor. By adjusting the speed of the motor through the medium of the rheostat 22 the engine with which the governor is associated may be controlled or governed to operate or run at any desired predetermined speed.

The differential type gear unit I3 is located in the bottom of the housing I0 between the upstanding partitions i6 and I1. It is driven by the engine driven shaft II and the electric pilot motor i2 and consists of a cylindrical casing 32, a pair oi primary bevel pinions 34 and 35 and a pair of secondary bevel gears 36. The cylindrical casing 33 frtends horizontally and embodies fron't and rear end walls. The front wall. is provided with a forwardly extending tubular trunnion 31 which is journalled in a bearing 33 on the lower portion of the upstanding partition i6. The rear end wall of the casing of the differential type gear unit I3 is provided with a rearwardly extending tubular trunnion 32 and this, as shown in Figure 2, extends through, and is journalled in, a bearing 4t on the lower portion of the upstanding partition I1 and is axially aligned with the trunnion 31. The two trunnions 31 and 39 permit the casing of the gear unit to revolve or rotate about a horizontal axis. The bevel pinion 34 is disposed adjacent the inner face of the front end wall of the cylindrical casing 3S and is mounted on, and iixedly secured to, the end of a horizontal longitudinally extending shaft 4I. The latter, as shown in Figure 2, extends through, and is rotatably mounted in. the tubular trunnion 21. The front end of the shaft 4I terminates in the space between the front wall i4 and the upstanding partition I5 of the housing I0. The bevel pinion 25 is axially aligned with the bevel pinion 34 and is disposed adjacent the` engine driven shaft II and the bevel pinion 24 'l and serves to drive the latter from the former. Such gear train comprises a pinion 44, a gear 45 in mesh with the pinion 44, a pair of meshing spiral gears '46 and 41 and a pair' of meshing spiral gears 42 and 49. The pinion 44 is disposed in the upper front portion of the space between the upstandlng partitions I2 and I1 and is xedly connected to the inner end of the engine driven shaft II. The gear 45 is driven by the pinion 44 and is disposed beneath the latter. It extends transversely of the housing and embodies a hub 52 which is surrounded and rotatably supported by a ball bearing 5I. The outer race of such bearing ilts within a circular hole l2 in the central portion ofthe partition I2. The spiral gear 42 is connected to the front end of the hub by way of a crosswall It, as shown in Figure 2.

,'iheapiralgearisdrivenbythespiralgear and is mounted on, and xedly secured to the upper end of a vertically extending shaft 5l. The latter is located directly in front .of the partition Il and is `iournalled in a bearing Il which is mounted on the front face of sai/d partition It. '11de spiral gear 4l is ilxedly connected to the lower end of the shaft 54. 'I'he spiral gear Il is driven by the spiral gear u and is ilxedly connected to the front end of the shaft Il for the pinion $4. When the shaft II is driven the gear train serves t6 drive the ybevel pinion ll of the differential type gear unitrll. Because of the design and character of the\gear train the bevel pinion Il is driven in a clockwise direction as viewed in Figure 5. A gear train It extends between the armature shaft 21 and the bevel pinion Il and serves to drive the latter from the former. As shown in Figures 2 and 4 such gear train conslats of a pinion I1, a gear 5l in mesh with the pinion 51, a pair of meshing spiral gears 5l and il, and a pair of meshing spiral gears 6I and 82. 'nie pinion 51 is the same in size as the pinion u and is mounted on, and flxedly connected to, the inner end of the amature shaft 21 of the. electric pilot motor I2. The gear 5I is driven by, and disposed beneath, the pinion 51 and is the same in size as the gear 45 of the gear train 4I. It extends transversely of the housing i 0 and `hasa hub il. The latter is surrounded, and rotatably supported by. a ball bearing 6l, the outer race of which is mounted in a circular hole B8 in the central portion of the upstanding partition i1. The spiral gear 58 is disposed in the space between the partition I1 and the rear wall Il of the housing and is connected to the hub Il of the gear 58 by way or" a crosswall lt. The spiral gear 8l is driven by the spiral gear 5! and is mounted on the upper end of a vertically extending shaft 61. The latter is Journalled in a bearing Il which is secured to the rear face of the partition i1. The spiral gear 62 is driven by determined speed the bevel pinion u rotates at the spiral gear Il and is mounted on, and keyed or otherwise nxedly secured to, the rear end of the shaft 42 for the bevel pinion 35. When the electric pilot motor is in operation the gear train 56 serves to drive the bevel pinion 35 from the armature shaft 21 of the motor. Because of the arrangement and design of the gear train 56 the bevel pinion is driven reversely to the pinion 3|. The bevel gears 3i are disposed in opposed and spaced apart relation and mesh with the bevel pinions Il and 35. They are disposed in, and extend lengthwise of, the cylindrical casing I3 and embody outwardly extending, centrally disposed stub axles il. The latter, as shown in Figure 2, are Journalled in bearings 10 on the inner face of the side wall of the casing 33. `When the engine driven shaft I I is driven at the same speed as the armature of the electric pilot motor due to the fact that the engine with which the governor mechanism is associated is running at its undetermined speed the bevel pinions Il and of the differential type gear unit Il rodium of the bevel gears 38 to rotate the casing d ille gear unit in a clockwise direction as viewed h ligure 5. In the event that the engine de- `creases in speed, i. e., decelerates from its prea lower or less speed than the bevel pinion Il and operates through the medium of the bevel gears 3i to rotate the casing 3l in a counterclockwise direction as viewed in Figure 5.

As previously pointed out the governor mech anism is adapted to control or govern the speed of the engine with which it is associated by varying the angle or pitch of the propeller blades of the controllable pitch propeller. The controllable pitch propeller which is disclosed in, and forms the subject matter of, United States patent application Serial No. 498,367, iiled on August 12. 1943, by Archibald G. Forsyth, now abandoned, represents one form or type of controllable pitch propeller with which the present governor is designed for use. Such controllable pitch propeller includes in addition to a hub and axially rotatable blades on the hub, pitch change mechanism comprising a magnetic clutch type device for effecting increase in the pitch of the propeller blades and a magnetic clutch type device for effecting decrease in the pitch of the propeller blades. The increase pitch device is controlled by a normally open push button switch 1I and the decrease pitch device is controlled by a normally open push button switch 12. The two switches are located in the sub-housing 2l. They are positioned one directly opposite the other and are arranged so that the buttons thereof face or oppose one another and are spaced apart a small distance. The switch 1| for the increase pitch device is mounted on a block-like carrier 13 in the outer portion of the sub-housing 2l. The other switch, i. e., switch 12, for the decrease pitch device is mounted on a block-like carrier 1l in the inner portion of the sub-housing 2i. The two carriers are cross connected by way of a plate 15. The latter embodies a laterally extending sleeve type bracket 16 which is slidably mounted on a suitably supported horizontal rod 11 in the sub-housing 2|. The plate 1I together with the bracket 16 and the rod 11 supports the two switch carriers so that they are conjointly slidable horizontally in either direction. A transversely extending diagonally positioned arm 18 is disposed in the sub-housing 2i and is arranged so that the lower end thereof extends between the buttons of the switches 1i and`12. When the carriers 13 and 14 are shifted towards the front of the front wall I4 of the housing I0 the switch 1| for the increase pitch device is closed as the result of the button thereof striking against, and being urged inwards by, the lower end of the arm 1I. When the two carriers are comointly shifted in the opposite direction, i. e., away from the front wall of the housing the switch 12 for the decrease pitch device is closed as the result of the button thereof contacting and being urged inwards by the lower end of the arm 1l. The arm 1l is supported by a horizontally extending pin 19. The latter extends lengthwise of the housing and has the front end thereof suitably attached to the central portion of the rear wall l5 of the housing Ill. The rear end of the pin extends through a transverse open ended hole in the central portion of the arm 18 with the result that the arm is permitted to slide horizontally. Said arm, except in connection with abrupt acceleration or deceleration of the engine, remains stationary. A pair of gears Il and l2 and a horizontal longitudinally extending screw shaft Il serve coniointly to shift the switch carrying carriers 13 and 14 in response to rotation of the cylindrical casing n The inner part is in frictional engagement withy the outer part. Under normal torques the outer and inner parts rotate as a unit. Should, however, the electric motor l2 stop for any reason whatsoever, or should there be a great difference in the speed of the engine driven shaft and the speed of the armature shaft of the motor the outer part 82b will slip relatively to the inner part and thus prevent injury to the various operating elements or members of the governor. Said screw shaft is journalled in bearings on the upstanding partitions I6 and Il and is suitably held against axial displacement. The rear end of the screw shaft extends into an internally threaded socket 84 in a bracket 85 on the plate 15. The screw thread connection between the screw shaft 83 and the bracket 85 is so designed or arranged that when the screw shaft is rtated in a counterclockwise direction as viewed in Figures 3, 4 and 5, due to clockwise rotation of the casing 33 of the differential gear type unit IJ'in response to acceleration or over speeding of the engine driven shaft Il the carriers 18 and I4-for the switches 1| and 12 are shifted towards the front wall I4 of the housing I0, thus result-- ing in closing of the switch 1| for the increase .pitch device of the controllable pitch propeller.

screw shaft 83 is 'driven by the gears '8i and I2' in aclockwise direction as viewed in'Fi'gures 3, 4 and 5, and results in the carriers 13 and 1I being shifted rearwards, i. e., away from the front wall I4 of the housing I0. Rearward shift of the two carriers results in closing of the switch I2 for the decrease pitch device and such device when energized or actuated causes the blades of the propeller to decrease in pitch, thus effecting an increase in speed of the engine. When the en gine driven shaft I I is rotating at the same speed as the armature shaft of the electric pilot motor i2..due tothe engine running at its predetermined speed .the casing of the differential type gear `unit I3 is stationary or at rest and the carriers 13 and 'Il are so positioned with respect to the arm 18, that the switches 1l and 12 are in their open position. Should, however, the engine increase in speed for any reason whatsoever the carriers are shifted towards the front wall of the housing with the result that the switch 1| for the increase pitch device is closed and such device, as previously pointed out, effects increase in pitch of the propeller blades with the resultant decrease in the speed of the engine. Should the engine decrease in speed for any reason whatsoever the carriers are shifted away from the front wall of the housing with the result that the switch 'I2 for the decrease pitch device is closed and such device operates to decrease the pitch of the propeller blades and effect corresponding increase in speed of the engine. The differential type gear extending radial lug=82 and the rearv endof the ment of the plungers in the direction of the lug 82. i

The compression springs 9'!v are disposedv in the l unit la together with its auxiliary parts includingA the gears 8| and 82 and the'screw shaft Il. is

essentially slow acting and is relied upon to effect governing of the engine in connection with gradual acceleration or deceleration of the engine.

In addition to the parts heretofore described the governor mechanism includes mean-s independentof the difieren/tial type gear unit' for substantially instantaneously bringing the engine backt'ol its predetermined speed in connection with abrupt or sudden acceleration or deceleration thereof. Such means comprises a floating flywheel type member 88 and a slide rod 81. The member 88 surrounds and is rotatable to a limited extent relatively to a horizontal sleeve 8l. 'Buch sleeve extends lengthwise of the housing Il-"of l the governor mechanism and is located between and inaxial alignment with the gear Il of the gear train and the gear 58 of the gear train "."l The front end of the sleeve iits within, and is keyedv or otherwise fixedly securedto, the hub hub 90 and this extends loosely around the central portion of the sleeve and is supportedl by The-inner-` way of a pair ofball bearings 8|. ra'ces of the bearings are fixed to the sleeve 88 andthe outer races are seated in annular grooves` in the hub 90"of the flywheel type member 885'- The two bearings 8l support the'member soj that it is rotatable relativelyto the sleevewhich, as previously pointed out, is connected for drive by. the gear l5. The rear end of the' annill'arjhub 90 of the member 86 is provided with-an outwardlyy sleeve' is provided with an outwardly extending annular flange SB-'as best shown in Figures 2 andvv 6. Thel flange is provided on' the front face thereofi'with' a pair of cppositely-'dispo'sed 'and op.. positely acting spring devices v84 and these coact'.v with -thellug 92Jto connect .the fioatingywheel' type member 86 "for drive by the sleeve 88 while" sists of tubular shells 85, plungers 80. and com-v' pression springs 81. The shells are suitably connected to the front face of the annular flange Il The inner v ends of the shells, i. e., the ends that are'adjacent and are'in longitudinal alignment.

or near' one another, are provided withinwardly extending anges 98 and the outer ends of the'y shells are provided with screw plugs 88.1 The f plungers 96 have the inner ends thereof in abutment. with the sides of the lug 82. The outer ends of the plungers embody enlarged heads 1087,'. z which iit slidably within the shells and coact with the inwardly extending annular flanges '881i "at lthe inner ends of the shells to limit sliding moveshells and extend between the heads |08 and the screw plugs 89. By turning the screw plugs vthe loading of the springs may be adjusted or varied. The spring devices 94 normally cause the floating ywheel type member 86.to rotate conjointly with the sleeve 88. However. in connection with abrupt 9 acceleration of the engine as may occur when the airplane is placed in a steep diving attitude the devices permit the member 88, due to its inertia, to underrun the sleeve 88 to a limited extent. In the event that the engine with which the governor mechanism is associated abruptly or suddenly decelerates, as, for example, may occur when the airplane is placed in a steep climbing angle or attitude,` the spring devices 88 permit the member 88, due to its momentum, to overrun to a limited extent the sleeve 88. After abrupt acceleration or deceleration of the engine the spring devices return the member 88 to its normal position with respectto the sleeve 88. The slide rod 81 extends lengthwise of the housing I8 and has its rear end operatively connected to the upper end of the arm 18 by a ball bearing I8I and its front end operatively connected to the floating flywheel type member 88 by a cam arrangement |82. The central portion of the slide rod extends through, and is slidably mounted in, a bore |03 in the crosswall 88 and the helical gear 88. The front end of the slide rod embodies an enlarged hollow head |08 and this is slidably mounted in the sleeve 88 and is con nected for drive by the sleeve while at the same time it is permitted to slide longitudinally towards and away from the front wall of the housing I8. The inner race of the ball bearing I| is shrunk around or otherwise flxedly secured to the slide rod 81 and the outer race is secured within a circular hole in the upper end of the arm 18. Because of the mode of mounting such inner and outer races the ball bearing IIiI permits the rod 81 to rotate relatively to the arm while at the same time it so connects the arm to the rod that the arm is shiftable with the rod. When the rod 81 is slid rearwards, i. e., away from the wall I I of the housing I0, the arm 18 is correspondingly moved and serves to close the switch 1| for the increase pitch device of the controllable pitch propeller. When the slide rod 81 is slid forwards the arm 18 is correspondingly moved and operates to close the switch 12 for the decrease pitch device. The cam arrangement |02 serves to shift the slide rod 81 in response to rotation of the member 88 relatively to the sleeve 88 in connection with `abrupt or sudden acceleration or deceleration of the engine. It consists of a diagonal cam slot |08 and a pin |08. The cam slot |05 is formed in the enlarged head |08 on the front end of the slide rod 81 and is so arranged that its leading end extends towards the rear of the housing I0 and its trailing end extends forwards, that is, in the direction of the front wall Il of the housing. The pin |08 is connected to, and extends inwards from, the annular hub 80 of the floating flywheel type member 88. The central portion of the pin extends through a circumferential slot |01 in the sleeve 88 and the inner end of the pin extends into the cam slot |85. The pin is so arranged that when the member 88 is in its neutral or normal position with respect to the sleeve 88 the inner end thereof is disposed in the central portion of the cam slot |05. The cam arrangement |02 is so arranged that when the pin is in the central portion of the cam slot as the result of the member 88 being in its neutral position with respect to the sleeve 88 the slide rod 81 holds the arm 18 midway between the buttons of the switches 1| and 12. Because the engine driven shaft I is rotated in a counterclockwise direction as viewed in Figure 5 of the drawings the sleeve 88 and the floating flywheel type member 88 revolve in a clockwise direction. When the engine abruptly or suddenly accelerates from its predetermined speed for any reason whatsoever the sleeve 88 overruns the member 88 due to the inertia of the latter and as a result of the inner end of the pin |88 of the cam arrangement |82 moves into the trailing end of the cam slot |80. Such movement on the part of the inner end of the pin operates to shift the slide rod 81 rearwards and thus cause the arm 18 to close the switch 1I of the increase pitch device thereby effecting slow down of the engine. When the engine abruptly or pronouncedly decelerates from its predetermined speed the floating flywheel type member 88, due to its momentum. overruns the sleeve 81 with the result that the inner end of the pin |88 moves into the leading end of the cam slot |08. Such movement on the part of the inner end of the pin causes the slide rod 81 to be shifted forwards thereby resulting in the arm 18 closing the switch 12 for the decrease pitch device and effecting speed up of the engine to its predetermined speed. As soon as the engine reaches its predetermined speed, or directly before, the member 88 is shifted by the action of one of the spring devices 88 into'its neutral or normal position with respect to the sleeve 88, thus resulting in the cam arrangement |02 shifting the rod 81 so as to return the arm 18'to its neutral or inoperative position with respect to the switches 1I and 12.

The operation of the governor mechanism is as follows:

When the speed of the engine corresponds to the speed determined or set by the electric pilot motor I2 the cylindrical casing 33 of the differential type gear unit I3 is stationary and the floating flywheel type member 88 rotates conjointly with the sleeve 88 and is so positioned by the spring devices 84 that the inner end of the pin |08 of the cam arrangement is disposed in the central portion of the cam slot |08. So long as the speed of the engine corresponds to the speed determined by the pilot motor |2 the buttons of the switches 1| and 12 are out of contact with the arm 18 and remain open. In the event that the engine gradually increases in speed for any reason whatsoever the gear unit I3, due to difference in the speed of drive of the bevel pinions 38 and v35, operates through the medium of the gears 8| and 82 and the screw shaft 83 to shift the carriers 13 and 14 towards the front wall Il of the housing I0. Such shift on the part of the carriers results in the switch 1| being closed due to abutment of its button with the lower end of the arm 18. As soon as the switch 1I is closed the propeller blades are increased in pitch with the result that the engine slows down or decelerates. When the engine slows down or decelerates to its predetermined speed the gear unit I3 shifts the carriers 13 and 18 back to their neutral position wherein the switches thereof are out of contact with the arm 18. In the event that the engine gradually decreases in speed for any reason ing either gradual acceleration or deceleration of the engine from its predetermined speed the oating flywheel type member 8l rotates con- Jointly with the sleeve 88 and the slide rod 81 remains in its neutral position. In the event that the engine should abruptly accelerate as a result of the airplane being placed in a steep or sharp dive the member 88, due to its inertia, underruns the sleeve i8 with the result that the cam arrangement |02 is substantially instantaneously brought into play and the shaft 81 is thereby shifted rearwards. Rearward shift on the part of the shaft 81 causes rearward displacement of the arm I8 and causes the arm to close the switch 1i thereby resulting in an increase in pitch of the propeller blades and diminution in the speed of the engine. Should the engine abruptly or suddenly decelerate from its predetermined speed as the result of the airplane being placed in an extremely high climbing attitude the member 8l, due to its momentum, overruns the sleeve Il and brings into play the cam arrangement ||2 in such manner that the latter causes the slide rod I1 and the arm 18 to move forwards. Forward movement on the part of the arm 'Il vcauses closing of the switch 12 and results in the propeller blades decreasing in pitch and the engine correspondingly increasing in speed.

By increasing or decreasing the speed of the electric pilot motor I2 through the medium of the rheostat 22 the engine will be governed so as to run at an increased or decreased predetermined speed: In other words, when it is desired to increase the speed of the engine to any deaired R. P. M. the rheostat is adjusted so as to decrease the amount of resistance in the motor circuit. If it is desired to decrease the speed of the engine the pilot motor is slowed down by manipulation of the rheostat so as to increase the amount of resistance in the motor circuit. By adjusting the rheostat the engine will be controlled automatically by the governor mechanism so tlat it operates at any desired predetermined spee Y The herein described governor mechanism is highly emcient in operation and effectively and eihcientiy fulfills its intended purpose. It is in the form of'a compact unit and responds substantially instantaneously to abrupt acceleration or deceleration of the engine with which it is associated.

Whereas the governor has been described as being particularly designed for use in connection with an airplane engine and as controlling the engine through the medium of a controllable pitch propeller it is to be understood that it may be used for other purposes and in other capacities. It is also to be understood that the invention is not to be restricted to the details set forth since these may bemodiiled within the'scope of the appended claims without departing from the spirit and scope of the invention.

Having thus described the invention what we claiilns as new and desire to secure by Letters Patent 1. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one of the driven parts of the engine, a second rotary member provided with means for driving it at a predetermined speed. speed control means, means operative automatically when the first mentioned member is driven at a speed different from the determined speed abruptly to actuate said speedA control means.

2. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one of the driven parts oi' the engine, a second rotary member provided with means for driving it at a predetermined speed, speed control means.- means including a differential type gear unit with certain parts thereof connected for drive by the members, respectively, and operative automatically when the first mentioned member is driven at a speed diierent from the second member due to gradual acceleration or deceleration of the engine from its predetermined speed gradually to actuate the speed control means, and means wholly separate from said differential type gear unit, including a rotary part connected for drive by the rst mentioned member, and operative automatically and substantially instantaneously when said first mentioned member is driven at a speed diierent from said second member due to abrupt or sudden acceleration or deceleration of the engine from its predetermined speed abruptly to actuate said speed control means.

3. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one of the driven parts of the engine, a second rotary member provided with means for driving it at a. predetermined speed, speed control means, means operative automatically when the first mentioned member is driven at a speed diierent from the second member due to gradual acceleration or deceleration of the engine from its predetermined speed gradually to actuate the speed control means, and cam means wholly separate from the fourth mentioned means, including a rotary part connected for drive by the first mentioned member, and operative automatically and substantially instantaneously when said iirst mentioned member is driven at a speed diiferent from said second member due to abrupt or sudden acceleration or deceleration of the engine from its predetermined speed abruptly to actuate said speed control means.

4. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected 'for drive by one of the driven parts of the engine, a second rotary member provided with means for driving it at a predetermined speed, speed controlling means, means including a differential type gear unit with certain parts thereof connected for drive by the members, respectively, and operative automatically when the first mentioned member is driven at a speed different from the second member due to gradual acceleration or deceleration of the I engine from its predetermined speed gradually to actuate the speed controlling means, and cam means wholly separate from the dierential type gear unit of the fourth mentioned means, including a rotary part connected for drive by the rst mentioned member, and operative automatically and substantially instantaneously when said ilrst mentioned member is driven at a speed diierent from said second member due to abrupt or sudden acceleration or deceleration of the engine .from its predetermined speed abruptly to actuate said speed controlling means.

5. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one of the driven parts of the engine, a second rotary member provided with means for driving it at a predetermined speed, speed controlling means including a pair of elements movable into and out of engagement with one another and adapted when in engaging relation to eifect actuation of the speed controlling means, means operative automatically when the iirst mentioned member is driven at a speed different from the second member due to gradual variation in the speed of the engine from its predetermined speed gradually to move one of the elements into engagement with the otherelement, and means separate from and in addition to the fourth mentioned means, including a rotary part connected for drive by the iirst mentioned member, and operative automatically and substantially instantaneously when said first mentioned member is driven at a speed different from said second member due to abrupt or sudden variation in the speed of the engine from its predetermined speed abruptly to move the other element into engagement with the one element.

6. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one of the driven parts of the engine, a second rotary member provided with means for driving it at a predetermined speed, speed controlling means including a pair of elements movable into and out of engagement with one another and adapted when in engaging relation to actuate the speed controlling means, means including a differential type gear unit with certain parts thereof connected for drive by the members, respectively, and operative automatically when the rst mentioned member is driven at a speed different from the second member due to gradual variation in the speed of the engine from its predetermined speed gradually to move one of the elements into engagement with the other element, and means separate from and in addition to the last mentioned means, including a rotary part connected for drive by the first mentioned member, and

operative automatically and substantially instan.

taneously when said rst mentioned member is driven at a speed different from said second member due to abrupt or sudden variation in the speed of the engine from its predetermined speed abruptly to move the other element into engagement with the one element.

7. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one of the driven parts of the engine, a second rotary member provided with means for driving it at a predetermined speed. speed controlling `means including a pair of elements movable into and out of engagement with one another and adapted when in engaging relation to effect actuation of the speed controlling means, means operative automatically when the iirst mentioned member is driven at a speed diierent from the second member due to gradual variation in the speed of the engine from its predetermined speed gradually to move one of the elements into engagement with the other element, and cam means separate from and in addition to the last mentionedmeans, including a rotary part connected for drive by the first mentioned member, and

, operative automatically and substantially instantaneously when said iirst mentioned member is driven at a speed different from said second member due to abrupt or sudden variation in the speed of the engine from its predetermined speed abruptly to move the other element into engagement with the one element.

8. A governor mechanism adapted to maintain an engine at a predetermined speed and comprising a rotary member provided with means whereby it may be connected for drive by one oi' the driven parts of the engine, a second rotary member provided with means for driving it at a predetermined speed, speed controlling means including a pair of elements movable into and out of engagementy with one another and adapted when in engaging relation to actuate the speed controlling means, means including a dierential type gear unit with certain parts thereof connected for drive by the members, respectively, and operative automatically when the first mentioned member is driven at a speed different from the second member due to gradual variation in the speed of the engine from its predetermined speed gradually to move one of the elements into engagement with the other element, and cam means separate from and in addition to the last means, including a rotary part connected for drive bythe iirst mentioned member, and operative automatically and substantially instantaneously when said nrst mentioned member is driven at a speed different from said second member due to abrupt or sudden variation in the speed of the engine from its predetermined speed abruptly to move the other element into engagement with the one element.

IRA J. SNADER. ARCHIBALD GRAHAM FORSYTH.

REFERENCES CITED The following references are of record in the me of this patent;

UNITED STATES PATENTS Number Name Date 40,754 Humphreys Dec. 1, 1863 639,470 Troubetzkoy Dec. 19, 1999 1,749,569 De Florez Mar. 4, 1930 2,160,324 Berges Hay 30, 1939 2,251,388 Bates Aug. 5, 1941 2,261,145 Dickey Nov. 4, 1941 2,326,308 Reissner Aug. 10, 1943 2,330,070 Martin Sept. 21, 1943 2,346,856 Martin Apr. 18, 1944 2,358,894 Volet Sept. 26, 1944 FOREIGN PATENTS Number Country Date 517,117 Great Britain Jan. 33. 1940 

